While setting up a local copy of a Magento based e-commerce site on my Windows machine, I was presented with a number of messages stating, "Fatal error: Call to undefined function money_format()." After a little research I was able to discover that this particular PHP function is not available on the Windows platform.
In order to get access to a version of the function that would be available from anywhere in the site's php code, I used the Apache auto_prepend_file directive in my php.ini file:
